Conduit for electric wires or cables.



No. 702,652. 'Pmm lune 17, |902.

(Application filed Apr. 10, 19.02.)

(lo Model.)

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UNITED STATES PATENT EEICE.

VROBERT w. LYLEQEPEETH AMEoY', NEW JERSEY.

CONDUIT FOR ELECTRIC WIRES OR CABLES.

SPECIFICATION forming part of Letters Patent No. 702,662,dated June 17, 1902,.

Application iiled April 10, 1902. Serial No. 102,169. (No model.)

To all whom it may concern:

Be it known that I, ROBERT W. LYLE, a

citizen of the United-States, residing at Perth,

Amboy, Middlesexcounty, New Jersey, have invented certain -new,ar 1d useful c.Improvements in Conduitsfor Electric Wires or Cables, of Which-the following is'a specification.

This invention =relates to`.conduits of'that class generally employed in underground electrical work, .in 'whiclruse they are intended for incasing wires,-cables, lor like conductors; and the invention primarily secures simple and highly-efticient means for lookin g and alin-v ing the respective sections of such conduit.

The conduits ordinarily used have one or' more openings, .recess es,-r";'seats inthe .webst or partitions thereof in whichdowel-pins lor their equivalents are seated,. the said pins being adaptedto enter registering or coinciding openings inthe abuttingends of-the said sections, being therebyintended to lock the same in alinement'.V -A' conduit thus made, however,possesses several serious disadvaul tages, chief among" which is the structural weakening of its sections by the formation of such holes, seats, or recesses therein in the manner set forth, which renders themexceedingly liable to breakage at or in adjacencefto such holes, openings, or seats,'and more'par-- ticularly when they are stacked up or are being transported. form these holes or openings in the conduit-s while the clay composing the same is in a semiplastic condition-rthat is, before it is burned oriired. When this latter operation is concluded, itA isfound that the partitions are frequently warped and at times to such an extent that when thedowel-pins or their equivalent are introducedlthey cannot be4 brought into absolute parallelism, thereby rendering the making of a close joint between;

and consequent alinement of the respective sections an exceedingly difficult and laboriousmatter.. Itis also evident that by reason of thelocation'ofthese dowel-pins they are very difcult to reach Vwhen the sections are being connected, so that considerable `time is thereby outlaid in forming the joint even if the pins project exactly straight from the ends of the sections. It will be understood that when making these joints the ends of the sections are very close together, abouttwo or three inches, so that the hands of the workman cannot be very well thrust between the ItfhasV been the ypracticejtoy same. By .my invention, however, these existin g defects are wholly overcome, and a conduit constructed n accordance with my invention can be as cheaply andv more easily made than the kind to which I have hereinbefore alluded, and the improved article,

.which in the form thereof represented in the accompanying drawings has one or more ex-- ternal grooves, is not appreciably weakened Vby the presence of such grooves.

It will be obvious from the following description and accompanying drawings that my improved conduit involves external lock- -ing and alining means for its respective section s,which may be of any desirable character.

`I n my copending application ied of even date herewith and having Serial No. 102,168, I have shown and described a conduit-section having external grooves atits opposite ends, the longitudinal side walls of which are undercut or beveled, and a coperating centering and locking key having its longitudinal edgesbeveled or shaped to correspond with the groovesin the conduit-sections. My present invention differs from that disclosed in the aforesaid application in that the end walls of the grooves are undercut or beveled, instead of the longitudinal side walls, and

likewise the centering andlocking keys have their opposite ends beveled or shaped tocor- 'respond with said beveledor uudercutend walls of the grooves.

In the accompanying drawings, forming av part of this specification, Figure 1 is a perspective view of a conduit-section embracing my invention. Fig. 2 is a side elevation, partly in section, of a conduit, showing the sections-thereof in alinement and an envelop aboutone of the joints between the sections thereof. Figs. 3 and filare sectional elevations of. modified forms of key and seat. Figs. 5,16," and `7 are-perspective views of suchkeys. Fig. 8 is an end view of a conduit-section, the keys being shownin section. f

4Like characters refer to like parts in all the iigures. l

The conduit-section is denoted ina general way by lO, audit may he made ofthev substance usually employed for this purpose, and` it has one or more interior passages or chambers extendingthe entire length of the same,

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as is customary, which are adapted to receive electric wires, cables, or the like. The said conduit-section is rectangular in'cross-section,

. displacement in an inward direction.

or substantially so; but the invention is not limited in this respect, for the sections may be of other shapes.

As hereinbefore pointed out, the sections of a conduit are customarily alined by dewelpins set into holes in the partitions ofthe same, such holes when the sections are conpled being brought into register, the holes in some cases extending the complete length and in others only a part of the length of the sections; but, as has been stated, these possess several drawbacks. My improvement contemplates the locking and alining of the respective sections of the conduit by external means, the same in the present'instance involving one or a plurality of grooves upon the outer surface thereof, and these grooves, unlike the doWel-pin holes, do not appreciably weaken the structure and located as they are are readily accessible during the union of the sections.

Referring to Fig. 2, it will be seen that the conduit-section there represented has a plurality of longitudinal grooves ll on each of its sides at each end, while in the form shown in Figs. l and 8 these grooves are on only three of the sides. In fact this is not essential, although I prefer to have the 'grooves on at least three of the sides. In like manner I may use only one groove at an end on each side of the conduit, and I consider such a construction within the scope of theinvention. It .will be seen that the respective grooves are arranged in parallelism directly opposite the partitions of the section and on reference to Fig. l that they extend simply a part ofthe length of the section IO and that one end of each groove is open, while the other end is closed, so that when a connector or key, hereinafter more particularly described, is inserted in said open end it can be moved backward unt-il it meets said closed end, whereby it is firmly held against longitudinal I prefer to undercut or bevel the end wall ll of the grooves, which can be accomplished in several different ways, as will hereinafter appear, so that when a connector or key of corresponding cross-section is fitted therein it is iirmly interlocked therewith and cannot possibly slip out sidewise when the sections are joined.

The grooves upon the exterior of the conduit-section l0 are adapted to receive keys, as I2, (shown in detail in Fig. 5,) and it will be seen on reference to this gure and also to Fig. 2 that the end walls of the keyare beveled, as at 13, so that they are maintained in place by a dovetail joint. These keys, it will be understood, are seated in complemental grooves or keyways registering with each other at the abutting ends of the sections l0 when the latter are assembled, the keys overlapping the joints between the sections on several sides thereof, and as the keys are locked firmly in position and as they are preferably upon three of the sides of the sections the latter are held securely in alined relation. In laying the conduits the keys l2 are first inserted in the grooves in one of the sections thereof, and the cooperating section is brought with its end inV proximity to the rst section, and the free ends of the keys are introduced into the grooves of said second section and the two parts are then moved into contact, each key, as will be understood, being seated for about half its length in registering grooves in the engaging ends of the respective sections and its ends abutting against the closed ends of such registering grooves. The keys may be made of any suitable material and shape, one desirable form thereof having been described. In Figs. 3 and 6 the end wall of the grooves ll"L and hence the end walls of the key 12;L are of ogee form, while the end of the groove or keyway lll (shown in Figs. 4 and 7) is stepped or angular in its cross-section, its key 12b being of similar shape, and it will be seen that in each case the grooves are so formed that the undercut end wall thereof is preserved.

The conduit at the junctions of its respective sections is enveloped or wrapped by sheets of asbestos, tarred cloth, or analogous sheet material, as 14, so as to assure close joints at these places, as shown-by Figs. 2 and 8.

The invention of course can be modified within the scope of the appended claims.

What I claim, and desire to secure by Letters Patent, is-

l. A conduit-section having a longitudinal external groove, the end wall of which is undercut.

2. A conduit-section having a longitudinal external groove, the end wall of which is beveled inward.

3. A conduit-section having a longitudinal external groove opening into one end thereof, the closed end wall of the groove being undercut, and a key' having an end shaped t-o fit in said undercut end wall.

4. A conduit the sections of which have registering external grooves the end walls of which are undercut, and a key fitted in each groove; the ends of the key being shaped to enter the undercut end walls ofthe groove.

5. A conduit the sections of which have registering external grooves the end walls of which are beveled, and a key fitted in each groove and bridging the abutting ends of the sections, the opposite ends of the key being beveled to iit under the beveled end walls of the grooves.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- DGSSGS.

ROBERT W. LYLE. Witnesses:

EDGAR W. WILLIAMs, ELIsAinn'rH WATTERS.

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